Compare the light-gathering powers of one of the Keck telescopes (10 m in diameter) and a 1.5 cm telescope.?

Question

Compare the light-gathering powers of one of the Keck telescopes (10 m in diameter) and a 1.5 cm telescope. Keck/1.5 cm =

Answer 1

The proportion of their light-gathering powers will be approximately equal to the ratio of their respective areas.

The area of a disk is pi r^2.

(pi)(10 m)^2 / (pi)(.0015 m)^2 or simply

the pi's cancel and you are left with

(10 m)^2 / (.0015 m)^2

Answer 2

that's subject-loose, a 10 meter telescope collects 2.8 circumstances as a lot comfortable as a 6-meter telescope will. that's assuming each and every telescopes' optics have coatings that replicate an identical share of sunshine, the equivalent comfortable loss as a results of the presence of the secondary replicate etc. In smart words, a 10-meter telescope will see instruments an entire value dimmer than a 6 meter telescope can, under an identical prerequisites on the equivalent internet internet internet site.